Handwheel for machine tools and the like



HANDWH EEL FOR MACHINE TOOLS AND THE LIKE Filed Dec. 28, 1964 Fig.1

United States Patent 3,315,540 HANDWHEEL FOR MACHINE TOOLS ARI) THE LIKE Paul Baumgfirtuer, Munich, Germany, assignor to Hans Deckel, Munich, Germany, and Friedrich W. Deckel, Zug, Switzerland Filed Dec. 28, 1964, Ser. No. 421,263 Claims priority, application Germany, Jan. 13, 1964, D 43,342 7 Claims. (Cl. 74-548) In various environments, there is a movable part which may be moved either by power or by a handwheel. Frequently the mechanism is so constructed that if the movable part is moved by the power operating means, this causes rotation of the handwheel. Such an arrangement is often found in modern machine tools, where for example both power feed means and handwheel feed means may be connected to a work table, a feed slide, or other suitable part. a

When the handwheel has a smooth periphery and no crank handle, the rapid rotation of the handwheel when the movable part is driven by the power operating means presents no particular hazard. However, if the handwheel has a crank handle permanently secured to the handwheel to turn therewith, then the rapid power-driven rotation ofthe handwheel with the protruding crank handle presents a hazard to a person in the vicinity.

An object of the present invention is the provision of a generally improved and more satisfactory handwheel, eliminating the hazard above mentioned.

. Another object is the provision of a handwheel having a hand crank which is normally disconnected from the handwheel and does not rotate with the handwheel when the handwheel is turned by other means, such as power means and which becomes automatically clutched or engaged with the handwheel when manual force is exerted to turnthe hand crank.

' Still another object, isthe provision of such a construction having means for automatically restoring the hand crank to its released or unclutched condition, when the manual pressure on the hand crank is released.

These and other desirable objects may be attained in the manner disclosed as an illustrative embodiment of the invention in the following description and in the accompanying drawings forming a part hereof, in which:

FIG. 1 is a View partly in elevation and partly in diametrical section taken axially through a handwheel in accordance with a preferred embodiment of the presentinven-v tion; and

7 FIG. 2 is a fragmentary rear view of a portion of the handwheel, viewed in the direction of the arrow A in FIG. 1.

A shaft 10 is operatively connected to the part or mechanism which'is to be moved by rotation of the handwheel, and which may in some cases (although not necessarily in all cases) be moved also by suitable power drive means. The shaft is provided with a collar 12. A key 14 provides a driving connection between the shaft and a surrounding bushing 16, which is held against axial displacement by a nut 18. Anotherkey on the outside of the bushing 16 keys the bushing to the handwheel 22, the hub of which is seated on the bushing. Thus the handwheel 22 rotates with the shaft 10 when. the shaft is 3,315,540 Patented Apr. 25, 1967 turned by other means, and serves to rotate the shaft when manual force is exerted to turn the handwheel.

The hub 24 of a crank indicated in general at 26 is freely rotatable on the free end or forward end of the bushing 16, and is secured against axial displacement thereon by means of a pin 28 extending through the hub 24 and engaging in a circumferential groove 29 in the bushing 16.

At its free end, the hand crank 26 is developed as a support for a handle 30 non-rotatably fixed to a pin 32 which is rotatable in a bore 33 in the hand crank, the bore extending parallel to the axis of rotation of the shaft 10. A disk 34 fixed to the pin 32 prevents the pin 32 and handle 30 from being withdrawn in an axial outward direction. A hub portion 36 is also fixed to the disk 34 and pin 32, these parts being integral with each other if desired. The hub 36 has an axial bore extending forwardly from its rear end, and internally threaded.

Mounted on the hub 36 is what may be termed a cam member 38, preferably in the form of an eccentric. The forward end of the eccentric member is in the form of a sleeverotatable on the hub 36, while the rear portion thereof is eccentric with respect to the axis of rotation of the sleeve portion. The eccentric member is pressed forwardly- (to the right when viewed as in FIG. 1) and thus frictionally coupled to the parts 34, 36 by means of a cup spring or disk spring 40, held by the enlarged head of a screw 42 firmly seated in the internal threads in the hub 36. In order to adjust the pressure of thespring 40 and thus adjust the degree of frictional coupling of the cam or eccentric member to the handle parts 30, 32, 34, 36, a disk 43 may be interposed between the cup spring and the adjacent bearing surface or shoulder of the eccentric, and a thicker or thinner disk may be substituted if it is desired to have greater or less coupling effect. This arrangement thus constitutes a slip clutch by which the eccentric 38 is carried along by the turning of the handle 30, but when the eccentric can turn no further, the handle 30 may still continue to turn by overcoming the frictional resistance caused by the pressure of the forward end of the sleeve portion of the eccentric on the rear face of the disk 34, and the pressure of the spring 40 and disk 43 against the forward face of the head of the screw 42 and the rearwardly faced shoulder on the eccentric.

In FIG. 2, the center of the eccentric portion of the cam member. 38 is indicated at 44, and the center of the axis of rotation thereof on the hub 36 is indicated at 46..

In the central or dead-center position of the eccentric, indicated in FIG. 2, the radially outermost edge of the eccentric is located a slight distance inwardly from a cylindrical or annular shoulder 48 formed on the rim of the handwheel 22. It is apparent from FIG. 2 that if the eccentric 38 is turned slightly in one direction or the other, the periphery of the eccentric willjam against the surface 48 of the handwheel, and thus will form a driving connection or clutch connection therewith. But when the eccentric is in its dead-center position, it will be slightly spaced from the rim of the handwheel and there will be no driving relationship between these two parts.

In order to tend to bring the eccentric back resiliently '3 urged radially outwardly by a spring 54. An enlarged head or plate portion 56 at the radially outward end of the shank 52 bears against a flattened portion 58 on the 'cam 38 in such manner that pressure of the spring 54 q tends to bring the eccentric part of the cam 38 into the -dead-center or normal rest position shown in the drawings.

If the operator grasps the handle 30 and starts to turn the crank, this will cause rotation of the handle 30 and,

the connected'parts 32, 34, 36, 42 relative to the crank. Through the frictional connection or slip clutch connection above described,.this will also start to turn the eccentric 38, until the periphery of the eccentric jams against the ledge or shoulder 48 on the rim of the hand-,.

wheel. This will establish 'a driving connectionlbetween the crank and the handwheel, so that further rotation of a the crank will correspondingly turn the handwheel, When the eccentric 38 has reached its jam-med or driving relation to the handwheel, it can turn no further relative to the crank 26, but the handle 30 can continue to turn on its own axis (as well as turning bodily, of course, around the axis of the shaft 10) by overcoming. the frictional resistance of the friction clutch between the handle and the eccentric.

So long as the operator continues to turn the handle 30 around the axis of the shaft 10, with a firm .graps, the

driving connection between the handle and the handwheel 22 remains elfective. As soon as the operator releases the handle 30, the force of the spring 54 restores the eccen tric to its dead-center position, breaking the driving connection between the handle and the wheel 22." If the wheel 22 is subsequently rotated by power means, the

crank'r26 and handle 30 will not rotate with it but will" remain stationary, so that the handle does not present a hazard to an operator who is in the vicinity.

The coupling between the crank 26 and the handwheel 22 can be either force-locked or form-locked. In this connection, a force-locked coupling is one in which coupling isproduced by frictional pressure of the coupled parts against. each other, rather than by any interfering shape of the parts, while a form-locked coupling is one in, which coupling force is transmitted on account of. interengaged shape of the parts, such as action of a. pawl against 'a ratchet tooth, or action of two teeth against each other. It is apparent from what has been said'above that the present construction may be used either with a 4 l axis of the shaft 10 may be described as a motion of revolution. Thus when the handle'is grasped tightly in'the hand of the operator and the crank is turned, the handle revolves about the axis of the shaft 10, it does not rotate relative to the hand of -the operator or relative to a fixed part of the machine, but it does rotate relatively to the crank 26, in a direction opposite to the direction of rotation of the crank itself. It is the rotation of the handle relative to the crank, while revolving around the shaft, that operates the coupling means.

'It is seen from the foregoing disclosure that the objects and purposes of the invention are well fulfilled. It is to be understood that the foregoing disclosure is given by way of illustrative example only, rather than by way of limitation, and that without departing'from the invention, the details may be varied within the scope of the appended claims.

What is claimed is:

1. A handwheel assembly comprising a handwheel" mounted for rotation and having .a shoulder concentric with the axis of rotationof saidhandwheel, a crank I mounted for rotation concentrically with said handwheel, 7 a handle mounted on said crank for rotation relative to" said crank about an axis offset from the axis of rotation,

of said crank, and a coupling member connected to said coupling member hasa central rest position in which said force-locked arrangement, using asmooth periphery onthe cam 38 and a smooth shoulder 48 on the handwheel,

or with a form-locked arrangement, in which the member 38, when turned from its rest position, makes positive engagement with teeth orthe like on the handwheel. Also it,- is apparent that the engaged surface of the handcrank is operatively disconnected from' said handwheel a so that said handwheel may rotate independently. of said.

crank, and is symmetrically formed with respect to said central rest position and so shaped that rotation of said coupling member relative to said crank in either direc-, .tion from said central rest position will couple said crank in driving relation to said handwheel,

3. .Aconstruction as defined in claim 2, further including spring means tending to return said coupling member to its said rest position.

4. A construction as'defined in claim inwardly toward the axis of rotation of said handwheel and crank, and in which said coupling member is' in the form of an eccentric member so mounted that its central 7' rest position is in dead-center relation to said shoulder wheel can be either faced inwardly on the rim of the a .wheel, or faced outwardly on the outer periphery or other suitable part of the handwheel. If engagement with the U 'outer periphery of the handwheel is preferred, it is de-' sirable although notessential to use a form-locked arrangement rather than a force-locked arrangement.

It is noted also that regardless of whether a forcelocked or a .form-locked'arrangement is used, in either case the locking member 38 is preferably symmetrical with respect to its released .or dead-center position, so

that rotation of the handle 30 ineithe'r direction will produce the desired locking relation between the crank and the handwheel; Moreover, it is also noted that with the specific shape of the parts here illustrated, any slippage after initial clutchingengagement of the parts will and is spaced therefrom, the axis of rotation of said ec I centric member being sli ghtly within the circle formed by said-shoulder, rotation of said eccentric member in 1 either direction from its restposition serving to bring f said eccentric member into jamming engagement with said member in a direction to jamit more? tightly, against 'tend to turn .the c am member38 further in a clutching f or driving direction rather than'in a releasing direction,

' thus, insuring'full driving relationship'as long as the opera- )tor continues to grasp the handle 30 and'turn it bodilyin-thedesired direction around the axis of the shaft 10.

The turning of the handle 300m its own axis (i.e., the

axis of the pin 32) may be described as a motion of rotation, and the bodily movement of the handle around the shoulder to form a driving coupling connection'between said crank and said handwheel, slipping of said eccentric;

member along said shoulder "tending to turn said eccentric said shoulder. a 5. A construction as definedin claim 4,

her to its said rest position. a

6. A construction as defined in claims, in which said j coupling member is connected at said handle 'by aslip. clutch, so that after said coupling'mem-ber reachesthe limit of its rotation relative to said crank in one direction,

said handle maycontinue to turn' relative to'said crank. I

7. A handwheel. assembly comprising a handwheel mounted for rotation and having a shoulder concentric" with' the axis of :rotation of said handwheel, "a crank, mounted for rotation concentrically withsaid handwheel, 1 7751 a handle mounted on 'saidcrank for rotation relative'to said crank about an axis offset from the axis of rotation of said crank, said handwheel being normally rotatable independently of said crank and without causing rota- 2, in which said a shoulder is of substantially smooth cylindrical shape faced a further includ- J mg spring means tending to return said coupling memtion of said crank, coupling means controlled by relative turning movement between said handle and said crank when said handle is grasped and revolved bodily about the rotary axis of the crank without rotation relative to a fixed part, said coupling means including a symmetrically 5 formed eccentric member so mounted that its central rest position is in dead-center relation to said shoulder and is spaced therefrom, and so that rota-tion of said eccentric member in either direction from its rest position serves to bring said eccentric member into engagement 1 References Cited by the Examiner UNITED STATES PATENTS 802,219 10/1905 Kleinman et a1. 74-548 X 1,595,277 8/1926 Wittel 74547 X 1,735,897 11/1929 Edgar et a1. 74-545 2,028,629 1/1936 Smith 192-8 FOREIGN PATENTS 55,492 3/ 1891 Germany. 70,853 9/ 1893 Germany.

FRED C. MATTERN, 111., Primary Examiner.

MILTON KAUFMAN, Examiner.

C. F. GREEN, Assistant Examiner. 

1. A HANDWHEEL ASSEMBLY COMPRISING A HANDWHEEL MOUNTED FOR ROTATION AND HAVING A SHOULDER CONCENTRIC WITH THE AXIS OF ROTATION OF SAID HANDWHEEL, A CRANK MOUNTED FOR ROTATION CONCENTRICALLY WITH SAID HANDWHEEL, A HANDLE MOUNTED ON SAID CRANK FOR ROTATION RELATIVE TO SAID CRANK ABOUT AN AXIS OFFSET FROM THE AXIS OF ROTATION OF SAID CRANK, AND A COUPLING MEMBER CONNECTED TO SAID HANDLE TO TURN THEREWITH RELATIVE TO SAID CRANK AND OPERATED BY ROTATION OF SAID HANDLE RELATIVE TO SAID CRANK TO ENGAGE SAID SHOULDER IN DRIVING RELATION THERETO FOR 